Apparatus and method for forming a scalloped edge on doctor blades



March 1965 .w. DOLL ETAL APPARATUS AND METHOD FOR FORMING A SCALLOPEDEDGE on DOCTOR BLADES 21, 1962 4 Sheets-Sheet 1 Filed Dec.

RE 012 W. bOLLEmd. EEimAN L1. DOLL,

INVENTORS LM*W A TTOP/VE Y5 March 2, 1965 s. w. oou. ETAL APPARATUS ANDMETHOD FOR FORMING A SCALLOPED EDGE 0N DOCTOR BLADES Filed Dec.

4 Sheets-Sheet 2 Mam}! 1955 s. W..DOLL ETAL 3,171,233

APPARATUS AND METHOD FOR FORMING A SCALLOPED EDGE ON DOCTOR BLADES FiledDec. 21, 1962 4 Sheets-Sheet 3 GREGORY W. boLL and.

B BRENBAN L. be LL.

INVENTORS 42 2 2 54g ATTORNEYS March 2, 1965 G. w. oou. ETAL 3,171,233

APPARATUS AND METHOD FOR FORMING A SCALLOPED EDGE ON DOCTOR BLADES FiledD80. 21, 52

4 Sheets-Sheet 4 GREGORY W. Don. and BRENBAN DOLL,

INVENTORS gummiwhwga ATTORNEYS United States Patent 3,171,233 APPARATUSAND METHOD FDR FORMING A SCALLOPEI) EDGE 0N DOCTGR BLADES Gregory W.Doll, 118 Oakwood Drive, Lenoir, N.C., and Brendan L. Doll, Patterson,NC. Filed Dec. 21, 1962, Ser. No. 246,523 12 Claims. (Cl. 513) Thepresent invention relates to an apparatus and method for forming ascalloped, working edge on a doctor blade, which doctor blade isparticularly adaptable for use with a paper making machine for removingthe web of paper from a drying cylinder with the scalloped edge thereofforming alternating longitudinal bands of coarsely and finely crepedareas of the paper.

It can readily be appreciated that the working edge of a doctor blade ofthis type must be very straight throughout its length, which length isusually considerable, so that the doctor blade will evenly andcompletely engage the drying cylinder of the paper making machine acrossthe face thereof. Also, the depressions in such a working edge must beof a predetermined depth and must be uniform in nature throughout thelength of the doctor blade so that all of the depressed areas of thedoctor blade will likewise evenly engage the drying cylinder. Otherwise,uneven wear will result on the surface of the drying cylinder, and thepaper may not be smoothly and completely removed from the dryingcylinder thereby interfering with the efiicient operation of the papermaking machine.

It has also been determined that the working edge of the doctor blade ispreferably beveled in the portions thereof between the depressions, sothat the areas of the paper which are removed from the drying cylinderby these portions will be coarsely creped as opposed to the finelycreped areas which are removed from the drying cylinder by the depressedareas. Also, such beveled portions provide a greater difference in thenumber of crepes per inch of the paper web between the coarsely andfinely creped areas thereof.

Prior to the present invention, no apparatus was available for forming astraight beveled edge on a doctor blade having spaced apart uniformdepressions therein. There were grinding apparatuses for grinding astraight working edge on doctor blades, but such apparatuses were notcapable of forming the desired bevel or the spaced apart, uniformdepressions therein. Therefore, doctor blades of this type haveheretofore been formed by manually moving a doctor blade and a grindingelement relative to each other to form the beveled edge thereon and thenmanually engaging the thusly beveled edge by a grinding element atspaced points therealong to form the spaced apart depressions.

It can readily be appreciated that such a manual operation requires ahighly skilled operator to achieve any degree of uniformity or accuracyin the beveling of the working edge and the forming of the depressionstherein. However, even the most highly skilled workman cannot readilyform the straight, beveled edge and the depressions therein with thenecessary degree of accuracy and uniformity to provide a satisfactoryWorking edge. Also, such manual operations are very tedious,time-consuming and resulted in great mental and physical fatigue in theoperator. In addition, such manual operations are very expensive.

It is therefore an object of the present invention to provide anapparatus and method for forming a scalloped working edge on a doctorblade of the type to be used in connection with a paper making machineto form alternating longitudinal bands of coarsely and finely crepedareas in the paper web wherein a doctor blade and a grinding element aremoved relative to each other for 3,171,233 Patented Mar. 2, 1965grinding a bevel on the one edge of the doctor blade to remove anyirregularities thereform and to thereby form a smooth, straight workingedge thereon and wherein spaced apart, uniform depressions are formed inthe thusly beveled working edge of the doctor blade by a second grindingelement.

A more specific object of the present invention is to provide anapparatus and method of the character described wherein the doctor bladeis continuously moved through a predetermined path past a grindingelement which bevels one edge of the doctor blade to form the straightworking edge and wherein spaced apart depressions are formed in thebeveled working edge by a second grinding element intermittently movedinto engagement therewith in timed relation to the movementof the doctorblade and while such movement is continued in an uninterrupted manner toform uniformly spaced depressions of uniform character.

Some of the objects of the invention having been stated, other objectswill appear as the description proceeds, when taken in connection withthe accompanying drawings, in which- FIGURE 1 is a front elevationalview of the apparatus of the present invention;

FIGURE 2 is a top plan view of the apparatus shown in FIGURE 1 with aportion broken away;

FIGURE 3 is a fragmentary vertical section taken substantially alongline 3-3 in FIGURE 2;

FIGURE 4 is a fragmentary sectional plan taken substantially along line44 in FIGURE 1;

FIGURE 5 is a fragmentary isometric detail looking in the direction ofthe arrow 5 in FIGURE 2 with portions shown in section;

FIGURE 6 is a fragmentary side elevational view looking from theright-hand side of FIGURE 1;

FIGURE 7 is an enlarged fragmentary elevation detail of a finisheddoctor blade according to the present invention; and

FIGURE 8 is a further enlarged fragmentary isometric detail takensubstantially along line S8 in FIGURE 7.

Referring now to the drawings, and more particularly to FIGURE 1, theapparatus of the present invention is generally indicated at 19.Apparatus 10 includes various operative elements which, whilecooperating to form the desired working edge on the doctor blade, willbe described separately under appropriate sub-titles for ease ofdescription.

Framework Apparatus 113 comprises a frame 11 which includes a first basemember 12 formed of suitable channel material and extending for the fullwidth of the apparatus 11). A second base member 13 (FIGURES 1 and 3) isformed in two sections with one section 13a being disposed on one sideof base member 12 and the other section 13!) thereof being disposed onthe opposite side of base member 12. Sections 13a and 13b are connectedto base member 12 by any suitable means such as Welding or the like (notshown) and extend laterally, outwardly from base member 12.

Frame 11 also includes a pair of end standards 14, 15 (FIGURE 1) mountedon base member 12 at opposite ends thereof and front and rear standards16, 17 (FIG- URES 1 and 4) mounted on base member 13 at opposite endsthereof. An intermediate standard 18 is mounted on base member 12intermediate the ends thereof and cooperates with end standard 14 tosupport a top frame member 19 which is mounted thereon at its oppositeends in vertically spaced, parallel relation to base member 12. Frontand rear standards 16, 17 support a top frame member 20 (FIGURE 2) whichis formed in two sections 20a and 2%, respectively, which are mounted 13on opposite sides of top frame member 19 in like manner to sections 13aand 13b relative to base frame member 12. Frame 11 further includes arectangular frame section 21 (FIGURE 4) including an end member 22mounted on the end of top frame member 19 at intermediate standard 18and having side members 23 mounted on opposite ends thereof and extendlaterally outwardly therefrom. The other ends of side members 23 areconnected to blocks 24 which are in turn mounted on opposite sides ofend standard 15.

A base frame member 25 (FIGURES 4 and 6) is connected at one end to theside of base member 12 at end standard and extends laterally, rearwardlytherefrom. The other end of base end frame member is connected to oneend of a base rear frame member 26 which is connected at its other endto the side of section 1312 of base frame member 13. A top end framemember 27 (FIGURES 2 and 4) is disposed above base end frame member 25and is mounted at one end on one of the side members 23 of frame section21. The other end of top end frame member 27 is connected to one end ofa top rear frame member 30 which is connected at its other end to oneside of section 20b of top frame member 20. Saidone end of top rearframe member 3% is supported above base rear frame member 26 by a postor standard 31 (FIGURE 6) which is mounted on base rear frame member 26and is connected to top rear frame member 30 at its upper end. A pair ofspaced apart, intermediate frame member 32, 33 (FIGURE 4) are mounted atone end on said one side member 23 of frame section 21 and are mountedat their other end on top rear frame member 30. mediate frame member 33is spaced from top end frame member 27 and cooperates therewith tosupport a cross frame member 34. A pair of spaced apart generally U-shaped frame members 35, 36 have the upper ends of the legs thereofmounted thereon and the bight portions thereof extending generallytherebetween, but at a lower elevation.

Turntable and drive therefor A preferably circular turntable 40 (FIGURESl and 2) includes a circular plate 41 having a flange 42 formed aroundthe periphery thereof. Flange 42 has a portion 42a (FIGURES 1 and 5)extending upwardly from plate 41 and a portion 42b extending downwardlytherefrom. A hub member 43 is mounted on the lower surface of thecentral portion of circular plate 41 and has an opening therethroughalined with an opening in the center of circular plate 41. It is notedthat the opening in the plate 41 is of a smaller diameter than theopening through hub 43. Four rib members 44 (FIGURES 1 and 2) areconnected at one end to hub 43 and extend radially outwardly therefromand are connected at their outer ends to the downwardly extending flangeportion 42b. The upper edges of rib members 44 are connected to thelower surface of plate 41 by any suitable means, such as welding (notshown). It is noted that flange 42, hub 43 and rib members 44 impart thenecessary rigidity to turntable 40.

A clamping device (FIGURES 2 and 5) is carried by plate 41 interiorly offlange 42 and includes a generally circular retaining band 45 whichterminates in spaced end portions. It is noted that retaining band 45 isformed of suitable resilient metal and normally has a diameter less thanthe diameter of flange 42 on plate 41 so that in relaxed condition,retaining band 45 is spaced inwardly from the upstanding flange portion42a.

Means is provided for spreading or expanding retaining band 45 to clampa doctor blade B between the reta-ining band and the upstanding flangeportion 42a with theedge of the doctor blade to be ground disposeduppermost. Such expanding means includes blocks 46, 47 (FIGURE 5)mounted adjacent opposite ends of retaining band 45 by any suitablemeans, such as welding, and

Interwhich have sockets (not shown) in the facing ends thereof. An overcenter latch mechanism is disposed between blocks 46 and 47 and includesan L-shaped latch member 50 having one leg 50a thereof longer than theother leg 5% and defining a handle for facilitating operation of thelatch mechanism. The shorter leg 50b of latch member 50 has a ball orrounded free end portion which is disposed in the socket in block 46such that latch member 59 may oscillate relative to block 46.

A second latch member 51 is pivotally mounted by a suitable bolt 52 onlatch member 50 at the point of juncture of the legs thereof forrelative pivotal movement. Second latch member 51 includes an adjustablebolt 51a which terminates in a rounded end portion which is disposed inthe socket in block 47 for relative oscillatory movement of second latchmember 51 relative to block 47. It is noted that when doctor blade B isof a length less than the circumference of plate 41, a spacer 53 may bedisposed between the spaced ends of the doctor blade when the same ispositioned between the retaining band 45 and the flange 42. It is notedthat the latch mechanism is retained in latched position when latchmember 50 is moved counterclockwise about pivot 52 (as seen in FIGURE 2)and thereby moves pivot 52 outwardly of a straight line drawn betweenthe sockets in blocks 46, 47 until the latch member 50 is manually movedin a clockwise direction (as seen in FIGURE 2).

A shaft 54 has a reduced upper end portion 54a (FI URE 5) which definesa shoulder 54]) at its juncture point with the remainder of shaft 54.Reduced end portion 54a penetrates through the opening in circular plate41 and is externally threaded for receipt of a washer 55 and a nut 56 toclamp the circular plate 41 downwardly against shoulder 54b. It is notedthat the remainder portion of shaft 54 is of substantially the samediameter as the opening through hub 43 and penetrates therethrough.

Shaft 54 isjournaled for rotation in a pair of bearings 57 mounted onbase frame member 12 and top frame member 19, respectively, by suitablebolts. Turntable 40 is thereby mounted for rotation on frame 11.

Turntable 49 is rotated by a large sprocket 60 (FIG- URES 1 and 2)drivingly mounted on shaft 54 and which supports one end of a sprocketchain 61. Sprocket chain 61 is supported at its other end by a drivesprocket 62 which is many times smaller than sprocket 60 (FIG- URE 4).Drive sprocket 62 is mounted on a shaft 63 (FIGURE 1) which is journaledfor rotation in a pair of spaced bearings 64. Bearings 64 are mounted ona bracket plate 65 which in turn is mounted on intermediate frame member31.

Shaft 63 has a sprocket 66 drivingly mounted on the other end thereofwhich supports one end of a sprocket chain 67 (FIGURE 4). Sprocket chain67 is supported at its other end by a sprocket 70 which is several timessmaller than sprocket 66 and is mounted on an output shaft '71 of aspeed reduction transmission 72 (FIG- URE 4).

Speed reduction transmission 72 is mounted on U-shaped frame members 35,36 and has an input shaft '73 on which is drivingly mounted a sprocket74 (FIG- URES l and 4). Sprocket 74 supports one end of a sprocket chain75 which is supported at its other end by a sprocket 76 which is severaltimes smaller than sprocket 74. Sprocket 76 is mounted on one end of ashaft 77 (FIGURE 4) journaled for rotation in bearings 8t) and has asprocket 81 drivingly mounted thereon. Sprocket 81 supports one end of asprocket chain 82 which is supported at its other end by a sprocket 83which is smaller than sprocket 81. Sprocket 83 is mounted on a shaft 84for rotation therewith which in turn is journaled for rotation inbearings 85 and has a pulley 86 drivingly mounted thereon. Pulley 86supports one end of a drive belt 87 (FIGURE 1) which is supported at itsother end by a pulley 90 mounted on output shaft 91 of a motor 92.

Motor 92 is mounted on a plate 53 by suitable bolts 94 and plate 93 ispivotally mounted at one end by a shaft 95. Shaft 95 is supported at itsopposite ends in spaced apart bearings 96 which are in turn mounted onbase frame member 12. It is noted that the pivotal mounting of plate 93permits the weight of motor 92 to maintain the proper tension in drivebelt 87.

Bearings 80 and 85 are mounted on a frame 161) (FIGURE 4) comprisingside members 191, 102 formed of suitable angle materials and end members1&3, 104 connecting side frame members 101, 1112 at their opposite ends.Frame 100 is in turn mounted on side members 23 of frame section 21 bybolts 105, 106 mounted on side members 23 and penetrating throughsuitable openings in side members 101, 102, respectively, of frame 100and being journaled at their inner ends in bearings 85. Frame 100 istherefore pivotally mounted on frame section 21 for movement about apivot defined by bolts 105, 106 which are in longitudinal alinement withshaft 84. Therefore, shaft 77 may oscillate about shaft 84 for reasonsto be presently described.

First grinding means A pair of spaced apart brackets 119, 111 (FIGURE 3)are mounted on standard 17 and the end of top frame member 20,respectively, and have mounted thereon one section 112a, 113a of splitclamps 112, 113. The other sections 112b, 11311 of clamps 112, 113 areadjustably mounted on sections 112a, 113a by bolts 114, 115 for movingthe split sections of the clamps toward and away from each other toadjustably clamp a column 116 therein. Column 116 has a sleeve 117mounted on the upper end thereof for sliding vertical movement relativethereto. Sleeve 117 is prevented from rotating relative to column 116 bya keyway 121) formed in column 116 and in which is disposed acooperating key (not shown) mounted on the interior of sleeve 117.

A bolt 121 (FIGURES 2 and 3) is mounted at one end on the upper end ofcolumn 116 and extends upwardly therefrom above the upper end of sleeve117. A hand wheel 122 is threadably mounted on the upper portion of bolt121 for rotation relative thereto and hence longitudinal movementtherealong. Hand wheel 122 includes a hub having a circumferentialgroove there around in which is disposed the portion of a plate 123defining a central opening therethrough in which the hub is disposed.Plate 123 is mounted on the upper end of sleeve 117 so that sleeve 117moves upwardly and downwardly along column 116 upon rotation of handwheel 122 in the appropriate direction.

A pair of clamp members 124, 125 (FIGURES 2 and 6) are mounted onopposite sides of sleeve 117 and extend laterally outwardly therefrom.Clamp members 124, 125 terminate in split portions at their outer ends,which portions have alined horizontal openings therethrough in which isdisposed a mounting bar 126 which extends inwardly toward turntable 40.Mounting bar 126 is adjustably clamped in clamping members 124, 125 bybolts 127, 128 to prevent rotation thereof, but to permit longitudinaladjustment thereof relative to the clamping members.

A U-shaped mounting member 136 has the bight portion 130a thereofmounted on the inner end of mounting bar 126 with the leg portions1301') thereof extending inwardly and upwardly therefrom at an acuteangle to the horizontal. Leg portions 13012 terminate in split clampportions (FIGURES 3 and 6) having alined openings therethrough and whichhave a pair of spaced apart bolts 131 therein for releasably clampingpivot pins 132 carried by the housing of a motor 133 for pivotallymounting the motor on mounting member 136.

Motor 133 has an output shaft 134 (FIGURE 3) on which is mounted a firstgrinding element or disk 135 (FIGURES 3 and 6). First grinding element135 is thereby positioned adjacent to turntable 40 for rotation about anaxis normally disposed at an acute angle to the vertical and is adaptedto engage the upper edge of the doctor blade B carried by turntable 40for beveling the same and to provide a straight smooth edge thereon.

Second grinding means A generally U-shaped bracket 136 (FIGURES 1 and 2)has the bight portion 136a thereof mounted on the upper end of endstandard 15 and has the legs 136b thereof extending upwardly therefrom.A mounting arm 137 is mounted at one end between the legs of U-shapedbracket by bolts 140 penetrating through alined openings therein forpivotal movement upwardly and downwardly about a horizontal pivotdefined thereby. Mounting arm 137 has a U-shaped bracket 141 mountedthereon adjacent its outer end with the legs extending upwardlytherefrom and terminating in split clamp portions having alined openingstherethrough. The split portions of the legs of bracket 141 arereleasably clamped together by suitable bolts 142 for clamping amounting bar 143 therein for adjustment inwardly toward or outwardlyaway from turntable 49.

Mounting bar 143 has a split clamp 144 (FIGURE 2) mounted on the endthereof adjacent turntable 40 which clampin ly mounts a sleeve bearing145 for lateral adjustment relative thereto. A shaft 146 is journaledfor rotation in sleeve bearing 145 and extends outwardly from oppositeends thereof. A second grinding element or disk 147 (FIGURE 1) isclampingly mounted on one end of shaft 146 (FIGURE 2) and a pulley 150is mounted on the other end of shaft 145. Pulley 150 supports one end ofa belt 151 which is supported at its other end by a drive pulley 152mounted on an output shaft 153 of a motor 154.

Motor 154 is mounted on the upper end of a bar 155 (FiGURE 6) which hasits lower end mounted in a sleeve 156 and is adjustably held therein bya lock screw 1 57 which is manually rotatable by means of a handle 157ainto and out of engagement with bar 155. Sleeve 156 is mounted at itslower end on cross member 33 by any suitable means, such as welding.

Means is provided for oscillating the pivotally mounted arm 137 upwardlyand downwardly relative to turntable 49 in timed relation to therotation thereof to thereby move second grinding element 147 carriedthereby into and out of engagement with the working edge of the doctorblade B to form spaced apart depressions D (FIG- URES 7 and 8) therein.Such means comprises an eccentric 160 (FIGURES 1 and 4) mounted on shaft77 for rotation therewith and around which is disposed a follower strap161. Strap 161 has an internally threaded nut 162 mounted thereon whichmatingly receives one externally threaded end portion of a connectingrod 163. The other end portion of connecting rod 163 is also externallythreaded but with an allochiral lead relative to said one end portionthereof. The other end portion is matingly mounted in an internallythreaded nut 164 mounted on the bight portion of a U-shaped connectinglink 165 which has the legs thereof straddling and pivotally connectedto a bracket 166 mounted on the lower surface of arm 137. The effectivelength of connecting rod 13 may therefore be varied by rotating the samein the appropriate direction.

Means is provided for controlling the elevation of the lower limit ofthe oscillatory movement of am 137 and hence second grinding element 147relative to turntable 40 to control the depth of the depressions beingformed in the doctor blade and to position the second grinding elementin an inoperative position wherein the same will not engage the doctorblade B. This means comprises a mounting frame 170 including a base 171on which are mounted the lower ends of legs 172a, 17% of an invertedU-shaped supporting bracket 172.- Bracket 172 includes a bight portion1720 which has a bearing 173 mounted on the lower surface thereof inwhich is journaled for rotation one end of a threaded shaft 174. Theother end of shaft 174 is journaled for rotation in a bearing 175mounted on base 171.

A bevel gear 176 is drivingly mounted on shaft 174 by a set screw 177and is disposed in meshing relation to a bevel gear 180 mounted on oneend of a shaft 181 for rotation therewith by a set screw 182. Shaft 181penetrates through and is journaled for rotation in an opening in leg172!) of bracket 172 and likewise penetrates through and is journaled ina bearing 183 mounted on vertical frame member 31. Shaft 181 penetratesthrough an opening in frame member 31 and extends outwardly therefrom. Ahand wheel 184 is mounted on the outer end of shaft 181 for facilitatingrotation of shaft 131.

A split nut 185 surrounds threaded shaft 174 and has an internallythreaded opening defined by the split portions thereof which matinglyreceives the threads of shaft 174. Split nut 185 is releasablymaintained in surrounding relation to shaft 174 by bolts 186. Split nut185 is connected to the lower end of a connecting member 187 whichextends upwardly therefrom and is connected at its upper end to endframe member 104 of pivotally mounted frame 100.

Operation In operation, a doctor blade to be ground is bent into acircular configuration and is positioned between flange portion 420 andretaining band 45 with one edge thereof resting on the upper surface ofcircular plate 41. If required, spacer 53 is positioned between flangeportion 42a and retaining band 45 between the ends of the doctor blade.

The doctor blade is then clamped in this circular configuration with thecenter of curvature disposed on the axis of rotation of turntable 40 bymoving handle portion 50:: counterclockwise until pivot 52 moves overcenter. Turntable 40 is then rotated by motor 92 by means of the beltand pulleys, and sprockets and sprocket chains connecting the same.

Prior to rotating turntable 40, grinding element 147 and its supportingarm 137 are pivoted upwardly relative to turntable 40 by manual rotationof hand wheel 184 which rotates shaft 181 and then shaft 174. Clamp nut185 is thereby moved upwardly which pivots the end of frame 100 on theopposite side of shaft 77 from shaft 84 upwardly about bolts 1G5, 106.Shaft 77 is thereby moved upwardly in an are having a radius equal tothe distance between shafts 77 and 84 which in turn moves arm 137upwardly through strap 161, connecting rod 163 and connecting link 165.The lower limit of oscillation of arm 137 and hence grinding element 147is thereby disposed above the upper edge of the doctor blade B clampedon turntable 40 so that grinding element 147 will not engage the same.

Grinding element 135 is then positioned relative to the upper edge ofthe doctor blade B by suitable rotation of the hand wheel 122 toposition sleeve 117 at the desired height on column 116 and the angle ofthe face of grinding element 135 is adjusted by pivoting motor 133relative to mounting member 130 to provide the desired bevel to theworking edge of the doctor blade. Preferably, grinding element 135 ispositioned at such an elevation relative to turntable 40 that the samewill grind away a slight amount of the upper edge of the doctor bladeupon the initial revolution thereof with turntable '46. Upon eachadditional revolution of the doctor blade B with turntable 40, grindingelement 135 is moved downwardly a slight amount until the desired depthof cut is formed on the upper edge of the doctor blade B to provide abeveled, straight working edge thereon.

While rotation of turntable 40 is continued, grinding element 135 ismoved out of engagement with the doctor blade B by suitable rotation ofhand wheel 122 and grinding element 147 is moved downwardly by rotationof hand wheel 184 in the appropriate direction to rotate shaft 181 andhence, shaft 174. This moves clamp nut 185 downwardly and pivots frameabout bolts 105, 106 in a clockwise direction as seen in FIGURE 1.Preferably, the grinding element 147 is positioned relative to turntable41 such that the lower limit of its oscillatory movement is slightlybelow the upper surface of the beveled edge of the doctor blade suchthat upon the initial revolution of the doctor blade, grinding element147 will remove a slight amount of this upper surface at spaced pointstherealong to form very slight depressions. After each revolution of thedoctor blade B by turntable 40, the lower limit of the oscillatorymovement of grinding element 147 is moved downwardly slightly until thedepres sions being formed by grinding element 147 are at the desireduniform depth. After the grinding operation is completeiturntable 40 isstopped and grinding element 147 is moved upwardly in the mannerdescribed above and the doctor blade B is released from turntable 40.

While the above-mentioned mode of operation is preferred, it is notedthat grinding elements and 147 may be operated simultaneously on theworking edge of the doctor blade B such that the working edge is beveledat the same time that the depressions D are being formed therein.

It will therefore be apparent that a novel apparatus and method forforming a scalloped edge on a doctor blade is provided wherein a beveledstraight working edge is provided and wherein spaced apart depressionsare formed in the working edge to impart a scalloped effect thereto sothat when the doctor blade is used in connection with a drying cylinderon a paper-making machine, alternating bands of coarsely and finelycreped areas of the paper will be formed.

In the drawings and specification there has been set forth a preferredembodiment of the invention and, although specific terms are employed,they are used in a generic and descriptive sense only and not forpurposes of limitation, the scope of the invention being defined in theclaims.

We claim:

1. A method of grinding an elongate doctor blade to provide a scallopededge thereon which when used in a paper-making machine forms alternatinglongitudinal bands of finely and coarsely creped areas in the paper,said method comprising the steps of (a) continuously moving the doctorblade and a grinding element relative to each other while (b) grinding abevel on one edge of the doctor blade,

and then (0) forming uniformly spaced depressions in the thusly formedbeveled edge to impart a scalloped appearance thereto by grinding thebeveled edge at closely spaced apart points therealong while (d)continuously moving the doctor blade and a grinding element relative toeach other.

2. A method of grinding an elongate doctor blade to provide a scallopededge thereon which when used in a paper-making machine forms alternatinglongitudinal bands of finely and coarsely creped areas in the paper,said method comprising the steps of (a) continuously moving the doctorblade in a predetermined path of travel past a grinding element While(1;) grinding a bevel on one edge of the doctor blade,

and then (0) uninterruptedly continuing the movement of the doctor bladewhile (d) forming uniformly spaced depressions in the thusly formedbeveled edge to impart a scalloped appearance thereto by intermittentlymoving a grinding element into engagement therewith for grinding thebeveled edge at closely spaced apart points therealong.

3. A method of grinding an elongate doctor blade to provide a scallopededge thereon which when used in a paper-making machine forms alternatinglongitudinal bands of finely and coarsely creped areas in the paper,said method Comprising the steps of (a) positioning the doctor blade ona rotatable member,

(b) continuously rotating the rotatable member and doctor blade thereonwhile grinding a bevel on one edge of the doctor blade,

and then a (d) continuing the rotation of the rotatable member anddoctor blade while (2) forming. uniformly spaced depressions in thethusly formed beveled edge to impart a scalloped appearance thereto byintermittently moving a grinding element into engagement therewith forgrinding the beveled edge at closely spaced apart points therealong.

4. A method of grinding an elongate doctor blade to provide a scallopededge thereon which when used in a paper-making machine forms alternatinglongitudinal bands of finely and coarsely creped areas in the paper,said method comprising the steps of (a) bowing the doctor blade into agenerally circular configuration,

(b) clampingly positioning the thusly bowed doctor blade on a rotatablemember concentric with the axis thereof and with the edge to be grounduppermost,

(c) continuously rotating the rotatable member and doctor blade thereonwhile (d) grinding a bevel on the edge of the doctor blade disposeduppermost, and then (2) continuing the rotation of the rotatable memberand doctor blade while (f) forming uniformly spaced depressions in thethusly formed beveled edge to impart a scalloped appearance thereto byintermittently moving a grinding element into engagement therewith forgrinding the beveled edge at closely spaced apart points therealong.

5. Grinding apparatus for forming a scalloped edge on an elongate doctorblade and the like comprising (a) means for supporting the doctor blade,

(b) first grinding means disposed adjacent said supporting means andengageable with one edge of the doctor blade for grinding a smoothuniform surface thereon,

(0) second grinding means disposed adjacent said supporting means andintermittently engageable with the ground edge of the doctor blade toform uniformly and closely spaced depressions therein to form ascalloped edge, and

(d) means for effecting relative movement between said doctor bladesupporting means and said first and second grinding means and beingoperatively connected to said second grinding means for intermittentlymoving said second grinding means into engagement with the edge of thedoctor blade.

6. Grinding apparatus for forming a scalloped edge on an elongate doctorblade and the like comprising (a) rotatable means for clampinglysupporting the doctor blade,

(b) first grinding means disposed adjacent said supporting means andengageable with one edge of the doctor blade for grinding this edge toprovide a smooth, even surface thereon,

(0) second grinding means disposed adjacent said supporting means andmovable toward and away from said supporting means, and

(d) means operatively connected to said supporting means for rotatingthe same to move the doctor blade past said first and second grindingmeans and operatively connected to said second grinding means forintermittently moving the same into engagement with the ground edge ofthe doctor blade to form uniformly and closely spaced apart depressionstherein.

7. The structure recited in claim 6 wherein said supporting means ismounted for rotation about a vertical axis and is adapted to support thedoctor blade thereon in a curved configuration concentric with the axisof said supporting means with the edge to be ground uppermost, andwherein said first grinding means comprises a grinding element mountedfor rotation about an axis disposed at an acute angle to the vertical tobevel the upper edge of the doctor blade and to form a smooth surfacethere- 8. A grinding apparatus for forming a scalloped edge on anelongate doctor blade and the like comprising (a) a frame,

(b) a turntable rotatably mounted on said frame for rotation about avertical axis, and including means for clamping the elongate doctorblade thereon in a curved configuration concentric with the axis of saidturntable and with the edge to be ground uppermost,

(0) first grinding means disposed adjacent said turntable and beingrotatable about an axis disposed at an acute angle to the vertical andengageable with the upper edge of the doctor blade for forming a smooth,uniform bevel thereon,

(d) second grinding means disposed adjacent said turntable and beingmounted for rotation about a horizontal axis and for intermittentengagement with the upper edge of the doctor blade to form uniformly andclosely spaced apart depressions therein to form the scalloped edge, and

(e) drive means for rotating said turntable to move said doctor bladepast said first and second grinding means and being operativelyconnected to said sec ond grinding means for intermittently moving thesame into engagement with the edge of the doctor blade.

9. The structure set forth in claim 8 wherein said turntable comprises acircular plate member having a vertical flange portion around theperiphery thereof and a generally circular retaining band mounted onsaid circular plate member interiorly of said flange portion andnormally being disposed in spaced relation to said flange portion, andover-center latch means operatively connected to said retaining band andoperable to move said retaining band into clamping relation with saidflange portion to clamp the doctor blade therebetween and saidovercenter latch means maintaining said retaining band in clampingrelation with said flange portion until released.

10. The structure set forth in claim 8 wherein first grinding meanscomprises a disc-like grinding element mounted for rotation about anaxis disposed at an acute angle to the ventical so that one of the facesthereof is engageable with the edge of the doctor blade, means forrotating said first grinding element, and means mounting said firstgrinding element for vertical adjustment relative to said turntable forvarying the depth of cut thereof on the edge of the doctor blade and foradjustment of the axis thereof relative to the vertical for varying theangle of the bevel formed on the edge of the doctor blade.

11. The structure set forth in claim 8 wherein said second grindingmeans comprises a second grinding element mounted for rotation about ahorizontal axis and in a plane radially of said turntable, means forrotating said second grinding element about said axis, means mountingsaid second grinding element for oscillation about a horizontal pivotspaced outwardly from the periphery of said turntable, said drive meansfor said turntable oscillating said second grinding element in timedrelation to the rotation of said turntable, and means for adjusting thelower limit of the oscillation of said second grinding element forvarying the depth of the depressions being formed in the edge of thedoctor blade.

12. A grinding apparatus for forming a scalloped edge on an elongatedoctor blade and the like comprising (a) a frame,

(b) a turntable rotatably mounted on said frame for rotation about avertical axis and comprising (1) a generally circular plate memberhaving a it vertical flange portion around the periphery thereof,

(2) a generally circular retaining band supported about said axis, andon said circular plate member interiorly of said flange portion andnormally being disposed in spaced relation to said flange portion butexpandable outwardly into clamping relation therewith for clamping thedoctor blade therebetween, and

(3) over-center latch means operatively connected to said retaining bandfor expanding the same outwardly into clamping relation to said flangeportion and being operable to maintain said retaining band in clampingrelation with said flange portion until released,

(0) means operatively connected to said turntable for rotating the sameabout said vertical axis, (d) first grinding means disposed adjacentsaid turntable and comprising (1) a grinding element mounted forrotation about an axis disposed at an acute angle to the vertical sothat one of the faces thereof is engageable with the edge of the doctorblade,

(2) means for rotating said grinding element (3) means mounting saidgrinding element for vertical adjustment relative to said turntable forvarying the depth of cut thereof on the edge of the doctor blade and foradjustment of the axis of the grinding element relative to the verticalfor varying the angle of the bevel formed on the edge of the doctorblade,

(e) second grinding means disposed adjacent said turntable andcomprising (1) a grinding element mounted for rotation about ahorizontal axis and in a plane radially of said turntable and adjacentthereto and adapted to intermittently engage the beveled edge of thedoctor blade at closely spaced points therealong to form uniformlyspaced apart depressions therein,

(2) means for rotating said grinding element about said axis,

(3) means mounting said grinding element for oscillation about ahorizontal pivot spaced outwardly from the periphery of the turntable,

(4) means responsive to rotation of said turntable for oscillating saidgrinding element about said horizontal pivot in timed relation to therotation of said turntable, and p (5) means for adjusting the lowerlimit of the oscillation of said grinding element for varying the depthof the depressions being formed in the edge of the doctor blade.

References Cited in the file of this patent UNITED STATES PATENTSAllison Dec. 24,

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,171,233 March 2, 1965 Gregory WQ Doll et a1.

It is hereby certified. that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 11, line 4, strike out "about said axis, and" and insert the sameafter "element" in line 25, same column 11.

Signed and sealed this 27th day of July 1965.

(SEAL) Attest:

ERNEST W. SWIDER' EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

5. GRINDING APPARATUS FOR FORMING A SCALLOPED EDGE ON AN ELONGATE DOCTORBLADE AND THE LIKE COMPRISING (A) MEANS FOR SUPPORTING THE DOCTOR BLADE,(B) FIRST GRINDING MEANS DISPOSED ADJACENT SAID SUPPORTING MEANS ANDENGAGEABLE WITH ONE EDGE OF THE DOCTOR BLADE FOR GRINDING A SMOOTHUNIFORM SURFACE THEREON, (C) SECOND GRINDING MEANS DISPOSED ADJACENTSAID SUPPORTING MEANS AND INTERMITTENTLY ENGAGEABLE WITH THE GROUND EDGEOF THE DOCTOR BLADE TO FORM UNIFORMLY AND CLOSELY SPACED DEPRESSIONSTHEREIN TO FORM A SCALLOPED EDGE, AND (D) MEANS FOR EFFECTING RELATIVEMOVEMENT BETWEEN SAID DOCTOR BLADE SUPPORTING MEANS AND SAID FIRST ANDSECOND GRINDING MEANS AND BEING OPERATIVELY CONNECTED TO SAID SECONDGRINDING MEANS FOR INTERMITTENTLY MOVING SAID SECOND GRINDING MEANS INTOENGAGEMENT WITH THE EDGE OF THE DOCTOR BLADE.